#!/bin/bash
# clickhouse-backup powers this recipe's backup/restore (the backupbot pre/post-hooks run
# `clickhouse-backup create/restore`). A deploy without it would have silently broken backups,
# so if it truly cannot be installed the deploy must FAIL LOUDLY rather than degrade.
#
# The published recipe fetched it with a single silenced no-retry wget at every container start:
# any transient GitHub failure exited the container (set -e) before clickhouse-server started,
# and the swarm restart loop re-downloaded the 22 MB asset on every restart, amplifying a
# throttle into a permanent crash-loop and a deploy timeout (cc-ci Q4.7).
#
# Hardening (no behaviour change when the fetch succeeds first try):
#   - cache the VERIFIED binary on the persistent clickhouse volume, keyed by version, so it is
#     downloaded at most once per app and container restarts never re-fetch;
#   - canonical Altinity URL (the project moved; the old AlexAkulov path is just a redirect);
#   - bounded retries with backoff + a read timeout, so a stalled connection cannot hang the
#     deploy and a transient failure cannot kill it;
#   - verify the binary actually executes before trusting or caching it (catches truncated
#     downloads and a corrupt cache);
#   - un-silenced: every attempt and the final verdict are visible in `docker service logs`.

set -e

CLICKHOUSE_BACKUP_VERSION=2.4.2

ARCH=$(uname -m)
if [[ $ARCH =~ "aarch64" ]]; then
  ARCH="arm64"
elif [[ $ARCH =~ "armv5l" ]]; then
  ARCH="armv5"
elif [[ $ARCH =~ "armv6l" ]]; then
  ARCH="armv6"
elif [[ $ARCH =~ "armv7l" ]]; then
  ARCH="armv7"
elif [[ $ARCH =~ "x86_64" ]]; then
  ARCH="amd64"
fi

CACHE_DIR=/var/lib/clickhouse/.ccci-bin
CACHED="${CACHE_DIR}/clickhouse-backup-v${CLICKHOUSE_BACKUP_VERSION}"
BIN=/usr/local/bin/clickhouse-backup
URL="https://github.com/Altinity/clickhouse-backup/releases/download/v${CLICKHOUSE_BACKUP_VERSION}/clickhouse-backup-linux-${ARCH}.tar.gz"

binary_ok() {
  "$1" --version >/dev/null 2>&1
}

install_clickhouse_backup() {
  mkdir -p "$CACHE_DIR"
  if [ -x "$CACHED" ] && binary_ok "$CACHED"; then
    cp -f "$CACHED" "$BIN"
    echo "clickhouse-backup: using verified cached binary ($CACHED)"
    return 0
  fi
  rm -f "$CACHED" # absent or fails to execute — re-fetch
  for attempt in 1 2 3 4 5; do
    if wget -T 30 --continue --output-document=/tmp/clickhouse-backup.tar.gz "$URL" \
       && tar -xf /tmp/clickhouse-backup.tar.gz --directory=/usr/local/bin --strip-components=3 \
       && binary_ok "$BIN"; then
      cp -f "$BIN" "$CACHED" 2>/dev/null || true
      echo "clickhouse-backup: downloaded, verified + cached (attempt ${attempt})"
      return 0
    fi
    echo "clickhouse-backup: fetch attempt ${attempt}/5 failed" >&2
    [ "$attempt" -lt 5 ] && sleep $((attempt * 10))
  done
  echo "clickhouse-backup: could not install after 5 attempts — failing the deploy (without it backup/restore would be silently broken)" >&2
  return 1
}

install_clickhouse_backup

exec /entrypoint.sh